Arc health lamp



1933- M. w. MOARDLE El AL 1,933,065

ARC HEALTH LAMP Filed June 28, 1929 4 Sheets-Sheet 1 I y j J 3;- Fr 7'8 Z .4 K

v 1 7 Z6) Z2 11 1 M 23 Oct. 31, 1933. M w, McARDLE ET AL 1,933,065

ARC HEALTH LAMP Filed June 28, 1929 4 Shegts-Sheet 2 96k 37 i \t 1&2 95 2 3- 1 1 14 4 HQ o O l v 144/ 93 I 101 5 l i 100 1 22' a 99 k. i :1 IEI I I l v j 95 1154 91 5 93 2 8f 2 3 b b a Q 1a Oct. 31, 1933. w MCARDLE ET AL 1,933,065

ARC HEALTH LAMP 4 Sheets-Sheet 3 Filed June 28, 1929 l zz 121 123 Oct. 31, 1933. M w. MCARDLE El AL 1,933,065

ARC HEALTH LAMP Filed June 28, 1929 4 Sheets-Sheet 4 108 @15 J? if M a; 88

/Z4 6 b I E Patented Oct. 31, 1933 PATENT OFFICE ARC HEALTH LAMP Michael W. McArdle and Ivar Jeppsson, Chicago,

Ill., assignors to Chicago Flexible Shaft Company, Chicago, 111., a

corporation of Illinois Application June 28, 1929. Serial No. 374,379

18 Claims.

Our invention relates to lamps of the type employing carbon electrodes for the production of radiant energy and deals particularly with a so-called therapeutic lamp.

Lamps of this kind are designed, insofar as possible, to duplicate the healthful energy of the suns rays. It has been found, for example, that the skin tan obtained from natural sunlight is, in a large measure, due to the light rays of higher frequency and to ultra-violet rays which lie above the visible part of the spectrum. In like manner many beneficial results .are attributed to the energy of longer wave length lying in the infra-red region.

Whilenumercus lights of this kind have been devised none of them are entirely satisfactory due, principally, to structure defects which hamper the functioning thereof. For example, many of them have required manual adjustment of the 20 distance between the carbons, which we shall call the arc gap, during the light treatment. adjustment must be made manually unless automatic means are provided since the ends of the electrodes burn away rapidly, the distance between them soon becoming so great that the electric current ceases to flow. The inconvenience of periodical manual adjustment during the light treatment will be obvious. Other lamps have been provided with automatic means for advancing the electrodes such as a solenoid but this is objectionable because of the great variation in the arc gap. By this method the electrodes are not advanced until the arc gap becomes so great that current ceases to flow 35 when the electrodes are brought almost in contact where they remain until they'have burned away sufiiciently to cause the current to again stop. lhis is undesirable for two reasons. Maximum light emission of the desirable character- 40 istics occurs within a certain verylimited range of gap distances. With the solenoid type of regulation the gap is within this range only a small proportion of the time which obviously results in a low efficiency. The power consumption varies inversely with the length of the gap, an excessive amount of electrical power being consumed when the gap is small and little when the gap is wide. It will-thus be obvious that the constant variation of the arc gap from very close to very wide is undesirable.

Other lamps have not been provided with suitable safeguards against accidental injury due to contact with the heated portions of the lamp or due to shock from contact with electrical parts thereof. Still other objections are the failure to provide suitable means for determining the length of the treatment periods and the like which are a sorce of inconvenience.

We have aimed to provide a lamp wherein the electrodes are advanced in a uniform manner substantially equal to the rate at which they burn away whereby a uniform length ofarc gap is maintained.

Another object of our invention has been the provision of a lamp embodying composite means 6 for advancing the-electrodes and shutting off the lamp at the conclusion of a predetermined treatment period.

We have also aimed to provide a lamp embodying highly improved safety features whereby the danger of accidental injury therefrom is materially reduced.

Another object has been the provision of a lamp wherein the most efiicient arc gap is automatically obtained at the start of the treatment 73 period and maintained substantially throughout the period by automatic means.

A still further object has been the provision of semi-automatic and highly improved means forresetting the electrodes after each treatment period. I I

Numerous other objects and advantages will become apparent from the following description and the accompanying drawings in Which- Figure 1 is a front elevation of the lamp showing timing dial, setting lever, and front door;

. Fig. 2is a rear view with the door in the open position, showing the space within for storing extra carbons and goggles;

Fig. .3 is a side view;

Fig. 4 is a top view showing the doors partly open;

Fig. "5 is a section on the line 55 of Fig. 3;

Fig. 6 is a section on the line 66 of Fig. .5 showing the "manner in which the clamping fingers are mounted;

Fig. 7 is a sectionon the line 7--7 of Fig. .5 showing the construction of the latching means;

Fig. 8 :a section on the line 88 of Fig. 5 showing the general arrangement of parts; I

Fig. .9 is a fragmentary view of the setting and advancing mechanism;

Fig. 10 is an elevation viewing Fig. .9 from the plane 10-10;

Fig. 11 is a section on the line. 11-11 of Fig. 10 showing the .coil spring between the two pinions;

Fig. 12 is a section on the line 1212 of Fig. 5 showing the switch and manner of mounting the lower electrodes; and

Fig. 13 is a wiring diagram of the lamp.

The device contemplates in a general way the provision of one or more carbon arcs supported in a suitable cabinet equipped with safety devices to prevent adults and more especially children from being accidentally injured from electric shock or burns from contact with the interlor of the lamp. Devices are provided for Seil'ilautomatically setting the carbon arcs and for advancing the electrodes at the same rate as they burn away to maintain an arc gap of uniform distance during all but the very last of the burning time when the lamp is being extinguished. A dial is also provided to permit the operator to so set the mechanism that the lamp will be automatically extinguished at the end of the desired treatment period.

Referring particularly to Figs. 1 to 4 the embodiment illustrated includes a cabinet as shown having front and rear frame plates 15 and 16, respectively, connected by a sheet metal side member 17 which extends completely around the frame plates to form a top 18, bottom 19, and sides 20 and 21. Front and rear doors, designated generally by 22 and 23 are attached to members 15 and 16 by means of hinges 24 and 2B suitably positioned upon the same side the cabinet. Each of the doors is provided with a plurality of openings 26 therein to permit the e of air into the cabinet and aid in the dissipation of the heat formed within. A glass 2! or other transparent material capable of transmitting the desired wave motions is positioned in the front door. A circular opening 28 is positioned to register with a dial 29, having a series of figures thereon to indicate the burning time of the lamp, when the door is closed, thereby permitting the dial to be positioned upon the front of the cabinet through the opening 28. The cabinet may be supported upon any suitable pedestal through a rod 30 and a fork 31 attached to the sides 20 and 21 by means of trunnions 32 and nuts 33. A mounting brack' et 34 connects the rod 30 with thefork 31 and the trunnlons 32 permit rotation of the cabinet on a horizontal axis, the nuts 33 serving to fasten the cabinet at different positions.

An electrode guard having a tube 35 is attached to the top 18 of the cabinet by means of rivets 36 and encloses an opening 37 as shown in Figs. 5 and 8, the rivets passing through flanged end portions 38 shaped to fit the cabinet. The upper end of said tube is covered by a top member 39 which is perforated to permit the passage of gases but prevents the operator from reaching the electrodes positioned therein and presently to be described. In order that the top member 39 of the guard be removable from the end of tube 35 to permit electrodes to be inserted therethrough it is supported from one side upon a strip 40 positioned in a slot in the front side of the tube 35 and hingedly attached thereto at 41. A rod 42 passing through openings 43 in the top 18 and 44 in the frame member 15 is plvotally attached to the strip 40 at 45 and at its opposite end bears against the front door 22 to prevent the member 39 from being opened when the door is closed and permit it to be opened with the door. This complete guard arrangement permits the electrodes to be positioned therein without danger to the operator and positively prevents children or others from coming in contact therewith While the electric current is'passing as will further be disclosed presently.

Directing attention to Figs. 5, 8 and 12, the cabinet is provided with an ash pan positioned in the bottom thereof under the electrodes for the purpose of facilitating the removal of the ash from the electrodes. The pan comprises a concave metal sheet 46 shaped to follow the con tour of the bottom 19 and having upturned front and rear flanges 47 and 48. Flange 47 has a knob 49 attached thereto for convenience in removing the pan. A small strip of mica 50 or other non-conductor is laid over the metal sheet 46 in order to prevent the lamp from becoming electrically charged should the lower electrode become loosened and drop into contact with the ash pan. The pan is arranged to be concealed by the door 22 when the latter is closed as shown in Fig. 8. Openings 51 in the bottom 19 of the cabinet are provided on each side of the ash pan to aid the circulation of air through the cabinet.

In order to lend rigidity to the cabinet and serve as a panel upon which the mechanism may be mounted a panel indicated generally by 52 is mounted in the cabinet. The panel isheld between the rear frame plate 16 and the sheet side member 17 and is seated therebetween by a series of bolts 53 which pass through eyelets 54 in the front and rear frame plates and draw the latter closely against the member 17. A space thus is provided between the panel 52 and the rear door 23 for the storage of extra carbon electrodes 55 which are positioned upright against the panel behind spring clamps 56 the bottoms thereof resting upon flanged sleeves 57. A pair of goggles 58 customarily employed in this type of light treatment may be positioned in said space in like manner by means of a. spring clamp 59.

Safety means are provided to prevent the doors from being opened accidentally or by children and is shown in detail in Fig. 7. Two latch levers 60 and 61 are pivoted in a U-shaped block 62 upon pins 63 fastened therein. The outer ends of the latch levers are formed into hooks 64 to engage latching hooks 65 and 66 l attached to the front and rear doors 22 and 23. A key 6'7 may be inserted in a keyhole 68 in the side 30 of the cabinet, the turning thereof serving to lift the latch levers 60 and 61 against the pressure of springs 69 and 70 to open the doors. The springs return the latch levers to latching position. It will be seen that the doors may not be opened without the key and the electrode guard 39 may not be opened until the doors are open.

To provide even greater safety in the operation of the lamp, automatic switching means are provided which automatically switch 03 the electric current when the front door is opened thereby preventing access to the interior of the cabinet when the lamp is in operation. Referring to Fig. 12, a rod 71 is placed horizontally alongthe side 20 with one end resting in an opening in the member 15 and the other extending well back of the panel 52. A pin '72 passes 3 through the rod near the end to prevent it from passing through the opening in the panel 52. A collar '73 provided with a central groove '14 adapted to engage the arm '15 of a toggle switch '16 is fixedly positioned on the rod '71 and a spring 77 urging it toward the front of cabinet. When the front door is opened spring urges the collar outward switching, electric current off in a manner which is vious.

the the the ob- When the door is closed the rod 15' forced inward, switching the electric current on. The electrodes and electrode supporting mechanism are mounted upon a bracket of strap metal having a portion 78 attached to the panel '52 by screws 79, a horizontal portion .80 bent at right angles thereto, and .a vertical portion 81 extending to the bottom 19 of the cabinet. A reflector designated generally by 82 is frictionally held between the portion 81 and the two sides of the frame plate 15 as shown in Fig. 12. The reflector may be of any metal having a polished surface and has on the rear surface thereof a layer of asbestos 8-3 or other suitable heat insulating material.

The lower electrodes 84 are supported by binding posts-85 which pass through opening 86 in the reflector and are attached to a piece of electrical insulating material 87 held between the member 81 and the reflector. Screws 88 serve to attach the binding post and hold the electrical connections as will presently be described. Wing screws 89 at the outer end of the posts 85 act to clamp the electrodes 84 in the slots 90.

A sheet metal member 91, positioned upon the upper side of the portion 80, extends forward to the front of the cabinet and is provided with rectangular openings 92 which permit ventilation and evacuation of the gases from the burn ing electrodes. A porcelain or other insulating member 93 rests upon the member 91 and electrically insulates the electrode support and resistance wires yet to be described. A plate 94 having an upstanding rod 95 rests upon the member 91 the rod acting as a guide for the mechanism supporting and guidin the upper electrodes 96, openings 97 in said plate permitting the electrodes to pass therethrough.

Fig; 9 shows in detail the means employed to support and adjust the upper electrodes 96. This consists in a U-shaped member having parallel 98 and 99 the lower arm 99 being upwardly bent at its outer end 100 and provided with slots 101 and 102 therein. Openings 103 and 104 permit the electrodes to pass vertically through the arms 98 and 99 and are sized to closely fit the electrodes yet permit them to slide freely. The rod 95 passes through the arms to guide their vertical movement. The arms 98 and 99 are connected together at their rear end by a portion 105 having a slot 106 out therein. A porcelain or other insulating block 107 is attached to the rear of portion 105 and is also attached to a vertical bar 103 the porcelain serving to insulate the arms 98 and 99 from the bar 108. A second bar having a horizontal portion 109 and a vertical portion 110 is positioned in the slot 106, the portion 109 resting upon a button 111. Two clamping fingers 112 having openings 113 normally disposed in registration with the openings 103 and 104, are loosely attached to the forward end of portion 109 through pins 114 and slots 115, the 'outer ends of the clamping fingers resting in slots 101 and 102. It will thus be seen that when the bar 110 is raised with respect to the arm 99, the fingers 112 will acquire an angularity pincha ing the electrodes 96 between the sides of the openings 113, as shown in Figs. 5 and 8, whereby with the openings 103 and 104 guiding the electrodes may be lifted upward thereby. In like manner it will be evident that when the bar 119 is lowered the clamping fingers will assume the position shown in Fig. 9 permitting the upper electrodes to slide freely under the force of gravity until they strike the upper end of the Fig. 10.

lower electrode 84. In order to insulate the vertical bar 110 from the cabinet and the remainder of the mechanism a block 116 of insulating materialis used to connect the former to a rack bar 117. c

The vertical bars 108 and 117 are each provided at the lower end with racks 118 and 119, respectively, arranged to engage pinion gears 120 and 121. Pinion gear 120 is fixedly attached to a shait'122 which serves as a mainspring shaft for a clock 123 and extends outward through the dial 29 at the front of the cabinet. The clock is thus arranged to drive the pinion gear 120 in a, counter clockwise movement and, through-the rack 118, lower arins98 and'99 at a predetermined rate of speed. The clock is of the type suited to this purpose adapted to be wound by clockwise movement of the shaft 122 and permittingnot only timed counter-clockwise movement but also permitting such movement of the shaft 122 by external means to lower the arms 98 and 99. A lever 124, shown to advantage in Fig. 10, having a pointer 125, cooperating with the dial 29, and knobs 126, and 126a is fixedly attached to the shaft 122 by means of a nut .127 The pinion 121 is fixedly attached to a sleeve 128 around the shaft 122 and is provided at its outer end with a lever 129;"naving a knob 130 and a projection 131 arranged to act as a stop against the lever 124. positioned to engage the opposite end of the lever 124 as a stop as indicated in dotted lines in A coiled spring 132 is positioned between the pinion gears 120 and 121 as shown in Fig. 11 and has one end fixed to each gear in a manner such that theigear 121, and with it 124, whereby rotation of the shaft 122 causes corresponding rotation of the sleeve 128. A layer of insulating material 133 is placed about the sleeve 128 to protect it from the heat and from possible electrical contact with the electrodes 84. The shaft 122 and the sleeve 123 are rotatably supported at their front end in a cross-member 134 placed across the rear of the plate 15 for the purpose. The rear ends thereof are supported from the clock which has bearing in the vertical member 81 through rods 135.

Referring to Fig. 13, the electrical energy is brought into the lamp through an insulated cord 136 to the switch 76 supported upon a U-shaped member 149 which is positioned between the panel 52 and the vertical portion 81 by bolts 150 and 151. A connection is made from the The knob 130 is iii switch to one of the electrode post bolts 88 through an. insulated wire 137, and from a second terminal of the switch through a wire 138, to a resistance element 139 which is in turn connected to a second resistance element 140 by a wire 141. The resistance elements are trained over porcelain insulators 142 supported on a bracket 143 attached to the panel 52 and having insulator arms 144. Bolts and nuts 145 serve to hold the resistance elements taut over the insulators. A Wire 146 connects the resistance element 140 with the second electrode post bolt 88. The upper electrodes are connected together by a bead insulated wire 147 having spring caps 148 at each end adapted to provide suitable contacts with the electrodes 96.

The operation of our improved lamp will be seen to be not only very safe but very simple.

With the doors closed the knob 126a is grasped 3.,

and the shaft 122 rotated until the pointer 125 indicates the time on the dial 29 desired for treatment. In so doing the holder for the upper electrodes is raised to the proper retracted position and the clock is suificiently wound. The two knobs 126a and 130 are then squeezed together rotating the sleeve 129 in a counterclockwise direction and releasing the upper electrodes as previously explained. The current will then begin to flow across the arc gap between the upper and lower electrodes. When the knob 130 is released the spring 132 will cause the clamping fingers 112 to be raised lifting the upper electrodes until the stop 131 comes in contact with the lever 124. This results in the most desirable arc gap. As the electrodes 84 and 96 burn away the clock feeds the supporting mechanism for the upper electrodes downward at a predetermined rate which is equal to the rate at which the arc gap tends to increase. When the lower arm 99 reaches the plate 94 the feeding will cease and the electrodes will burn away until the current will no longer flow.

It will thus be seen that we have provided a highly improved lamp of the character wherein it is impossible to gain access to the interior of the cabinet without the supply of electricity automatically being shut off. During the greator share of thetime the spark gap remains constant giving the maximum efficiency both from the standpoint of the character of radiation emission and the power consumption. It should also be observed that we have provided a novel manner of mounting the resistance elements wherein they are inaccessible to children and adults and provide a unitary device.

While we have thus described and illustrated a single embodiment of our invention we are aware that numerous alterations and changes may be made therein and we do not wish to limit ourselves except as required by the prior art and the appended claims in which-- 1. A lamp of the character described comprising a cabinet, front and rear closures for said cabinet, means for supporting said closures upon said cabinet to move between an open position to permit access to the interior of said cabinet and a closed position to prevent access thereto, electrodes positioned within said cabinet arranged to strike an are, means for connecting said electrodes with a source of electrical energy, an opening in said cabinet adapted to permit the feeding therethrough of at least one electrode, an electrode guard arranged to enclose said opening, means for preventing said guard from being moved from over said opening when the closures for said cabinet are in their closed position but permitting said guard to be moved when the doors are opened, a window of transparent material positioned in the front closure of said cabinet opposite the are formed by said electrodes, and a plurality of openings in said cabinet, said closures and said guard to permit the rapid dissipation of heat formed therein.

2. A lamp of the character described, comprising a cabinet, a front and a rear closure for said cabinet, means for supporting said closures upon said cabinet to move between an open position to permit access to the interior of said cabinet and a closed position to prevent access thereto, electrodes positioned within said cabinet arranged to strike an arc, means for connecting said electrodes with a source of electrical energy, means for automatically disconnecting said source of energy from said electrodes when said front closure leaves the closed position and reconnecting said source when said closure resumes the closed position, a window positioned in the front closure of said cabinet opposite the arc formed by said electrodes, a mounting panel within said cabinet adjacent to said rear closure for supporting mechanism of said lamp on the forward side thereof and for releasably supporting accessories on the rear side thereof, and a plurality of openings in said cabinet and said closures to permit rapid dissipation of heat formed therein.

3. A lamp of the character described comprising a frame, at least one upper and one lower carbon electrode arranged to form an arc, means for connecting said electrodes to a source of electrical energy, means for fixedly supporting one of said electrodes, means for adjustably supporting the second electrode, means including a clock for automatically advancing the second electrode and support at a uniform rate to maintain a substantially uniform arc gap as the electrodes burn away, stationary means acting against said adjustable support for stopping the advancement of said electrode, and means for simultaneously setting said adjustable support a predetermined distance from said stop and winding said clock.

4. A lamp of the character described, comprising a frame, at least one upper and one lower carbon electrode arranged to form an are, means for connecting said electrodes to a source of electrical energy, means for fixedly supporting one of said electrodes, spaced arms each having near one end a hole through which the second electrode is adapted to pass and connected at their opposite ends to form a U-shaped supporting member, means for frictionally clamping said second electrode in said holes, means for advancing and retracting said supporting member including a clock mechanism, whereby the second electrode is advanced at a uniform rate of speed to maintain a uniform distance between the carbons as they burn away, and means for electrically insulating said electrodes from said frame.

5. A lamp as set forth in claim 4 wherein said means for advancing and retracting said supporting member serves to advance said second electrode during a predetermined period of time and wherein means are provided for stopping said first mentioned means at the expiration of said time and holding said second electrode stationary to cause the gap to increase as said electrodes burn away and thereby break the arc between the electrodes at the expiration of a predetermined time total.

6. A lamp of the character described, comprising a frame, at least one upper and one lower carbon electrode arranged to form an are, means for connecting said electrodes to a source of electrical energy, means for electrically insulating said electrodes from said frame, means for fixedly supporting one of said electrodes, spaced arms each having near one end a hole through which the second electrode is adapted to pass, said arms being connected at their opposite end to form a U-shaped supporting member, means for frictionally clamping said second electrode in said holes, a clock, a shaft arranged to be driven thereby, a pinion positioned upon said shaft, a rack engaging said pinion near one end and attached to said supporting member near its opposite end whereby movement of said clock provides corresponding linear motion of said supporting member and second carbon causwas ingthelatter to be advanced at a uniform rate of speed to maintain auniform distance between the carbons as they burn away.

7. A lamp of the character described comprising a cabinet having a frame, front and rear closures for, said cabinet, at least two carbon electrodes arranged to strike an are, means for connecting said electrodes to a source of electrical energy, means for electrically insulating said electrodes from said frame, means for holding one of said electrodes in a fixed position, a support for adjustably holding the second elec trode. arranged to move between an advanced position and any one of a plurality of retracted positions dependent upon the desired operating time, means operable from the exterior of said cabinet for setting said support in a desired retracted position, to regulate the burning time of the lamp, and means including a clock and rack. and pinion for uniformly moving said support from its retracted position to its advanced position whereby a uniform gap is maintained between the electrodes as the carbons burn away until the support has reached its advanced position.

8. A lamp of the character described, comprising a frame, at least one upper and one lower carbon electrode arranged to form an arc,

means for connecting said electrodes to a source of electrical energy, means for electrically insulating said electrodes from said frame, means for holding the lower electrode in a fixed position, a support for holding said upper electrode comprising a plurality of parallelly disposed guiding arms and an intermediate arm adapted to frictionally grip and hold said electrode, said support being arranged to move between an advanced and retracted positions, means operable from the exterior of said cabinet for moving said support into any one of a plurality of retracted positions, means for releasing .said upper electrode from said support permitting said upper electrode to drop into contact with said lower electrode, means for grasping and withdrawing said upper electrode to a desired arc gap, and means for advancing said upper electrode in a uniform manner to provide a uniform are gap as the carbons burn away.

9. In a lamp of the character described having a plurality of electrodes, electrode guiding means, a clock, a rack connected to said guiding means, a pinion cooperable with said rack, means for manually turning said pinion in one direction to separate said electrodes said means being turned in the opposite direction in timed relation by said clock to bring said electrodes together, electrode clamping means, a

second rack connected to said clamping means,

a second pinion cooperable with said second rack rotatable with said first pinion and rotatable within limits with respect thereto, and spring means acting between said pinions to normally prevent relative rotation between the pinions.

10. A lamp of the character described in claim .9 having a cabinet, wherein such means for operator in manually turning said first mentioned pinion.

11. A lamp of the character describedin claim 9 having a cabinet wherein such means for turning the first mentioned pinion includes, a shaft Qupon which the pinion is fixedly supported connected to the clock. and: extending to the oxterior of said cabinet, devices attached to saidv shaft outside said cabinet to be grasped by the operator in manually turning said first mentioned pinion, andv a. dial graduated in. time units upon which said devices are arranged to indicate. the burning time of the lamp- 12.. In a lamp of the character described at least two electrodes: arranged to be positioned end to end. to provide an upper and a lower electrode, means for fixedly supporting. the lower electrode, an electrode guiding mechanism in which said upper electrode is slidably mounted, an electrode clamping and retracting mechanism arranged to move between an advanced position, in which said upper electrode is slidably held therein,uand a retracted position in which said upper electrode is fixedly held therein, to form. an arc gap between said upper and lower electrodes, means for retracting said clamping and. retracting mechanism, and means for lowering. said. upper electrode toward said lower electrodeat a uniform rate to maintain a constant arc gap as the electrodes become shorter.

13. A lamp as set forth in claim 12 wherein the means for lowering said upper electrode comprises a c1ock, a pinion attached thereto and actuated thereby, a rack supporting said guiding mechanism arranged to engage said pinion, a second pinion mounted to normally move with said first mentioned pinion but capable of movement with respect thereto, and a second rack supporting said clamping mechanism arranged to engage said second pinion.

14. In a lamp of the character described, at least two electrodes arranged to'be positioned end to end to provide an upper and a lower electrode, means'for fixedly supporting the lower electrode, an electrode guiding mechanism in which said upper electrode is slidably mounted to drop by gravity intocontact with said lower electrode, means for raising and lowering said mechanism, an electrode clamping and retracting mechanism adapted to move with said guiding mechanism arranged to move between an advanced position, engaging said guiding mechanism, in which said upper electrode is slidably held therein and a retracted position in which said upper electrode is firmly held therein, said upper electrode being released during the movement from the retracted to the advanced position and clamped and retracted during the movement from the advanced to the retracted position to form an arc gap of predetermined length between said upper and lower electrodes, and means for moving said clamping and retracting mechanism independent of said guiding mechanism between said advanced and retracted positions whereby said upper electrode may be lowered independently of said guiding means.

into contact with said lower electrode and retracted to form a predetermined arc gap.

15. In a lamp of the character described arranged to be intermittently operated for predetermined periods of time and having an enclosing cabinet, at least one upper and one lower electrode, means for holding said lower electrode, means for holding said upper electrode, means for feeding said upper electrode and upper electrode holding means during said operating period, and means manually actuatable from a point outside said cabinet while the current is on for advancing said upper electrode through said upper electrode holding means a predetermined amount at each operating period, the amount 9 depending upon the, length of said operating period.

16. A, lamp of the character described comprising a frame, at least two electrodes arranged to form an arc, means for holding said electrodes, means for connecting said electrodes to a source of electrical energy, means for automatically advancing at least one of said electrodes during a period of operation, said period being less than that required to consume all of said electrode, and combined means manually operable for advancing said electrode through said holding means to determine the length of said period oi. operation and for starting the period of operation.

17. A lamp as set forth in claim 12 having manually operable means for raising said electrode guiding mechanism and said clamping and retracting mechanism with respect to said upper electrode when said clamping and retracting mechanism occupies its advanced position to reset said mechanisms for feeding said upper electrode downward in a second cycle of operatlons.

18. In a lamp of the character described, electrodes arranged in a plurality of pairs, each pair consisting of an upper and a lower electrode, mechanical means for holding said upper electrodes including pivotally supporting fingers each having an opening slightly larger than said electrodes to receive the same, adapted to occupy a clamping position in which said electrodes are firmly held, and a releasing position in which said electrodes are free to drop under gravity, and means for raising and lowering said holding means to feed all of said upper electrodes downward at the same uniform rate comprising a clock actuated rack and pinion adapted to automatically regulate the downward movement, and a lever for manually actuating said rack and pinion in the upward movement and simultaneously winding said clock.

MICHAEL W. MCARDLE. IVAR JEPPSSON. 

